Automatic cut-out for electric-light circuits



UNITED STATES PATENT OFFICE.

CHARLES CUNO, OF IVAUVATOSA, VISCONSIN.

AUTOMATIC CUT-OUT FOR ELECTRIC-LIGHT CIRCUITS.

SPECIFICATION forming part of Letters Patent No. 497,491, dated May 16,1893.

Application filed April 16, 1892. Serial No. 429,413. (No model.)

To @ZZ whom t may concern:

Beit known that I, CHARLES CUNO, of Wauwatosa, in the county ofMilwaukee and State of IVisconsin, have invented certain new and usefulImprovements in Automatic Cut-Outs for ElectrieLight Circuits; and I dohereby declare that the following is a full, clear, and exactdescription of the invention, which will enable others skilled in theart to which it pertains to make and use the same, reference being hadto the accompanying drawing, and to the letters of reference markedthereon, which forms a part of this specification.

My invention is designed particularly for use in connection withelectric light plants furnishing lights at a cost based upon the averageor maximum number of lights used at any given time by any patron, andits main object is to automatically cut out of circuit the loop orbranch in which the lamps of a plant,buildingor apartment arelocated,when ever it is attempted to use a greater number of lamps thanis permitted, and to automatically re-establish the circuit through suchloop or branch, when the lamp or lamps in excess of the number permittedare turned off. Dwelling houses and other buildings, tenements orapartments are usually equipped with or for more lamps than are neededfor actual use at any one time, it being desirable to light differentapartment-s or portions of a building or'apartment at different timeswhile the lights in other apartments or portions of the building orapartment are discontinued, the average number of lights used at anygiven time being approximately constant. It is perfectly feasible andconvenient, particularly in connection with comparatively small plants,to tix the rate of charges for lights according to the average numberused by any patron, provided some absolutely certain check can be hadagainst the use of a greater number of lights than that upon which therate is fixed. To meet such requirement and to provide such a check, isthe design of my invention.

The accompanying drawing shows a front elevation of my improved cut out,the cover of the case being removed to disclose the interior mechanism.

For the purpose of illustration I have shown and will describe myinvention in connection with a three wire system, although it is equallyapplicable to the two wire system of incandescent lighting.

A represents a case of suitable shape and construction to inclose andprotect from interference the necessary mechanism. It is designed to beplaced at some convenient point. in a plant, building or apartmentsupplied with lamps, on a loop or branch of the main circuit.

B and O are the main wires leading in from the main circuit to theeutout, D and E are the corresponding wires leading out of the cut outto the lamps O O in the loop or branch, and F is the neutral wire.

`Gr is an arc-shaped solenoid, the windings of which are formed by orconnected with the wires B and C. A similarly shaped core g, of softiron, suspended at one end by an arm g from a horizontal axis g2,projects at the opposite end into said solenoid.

Attached to the axis g2 and movable with the core g of the solenoid, isametallic index Il, the free end of which moves over a graduated arc 7L,between two'contact pieces L h2, one Contact piece 71,2 being adjustabletoward and from the other contact piece 7L.

I is a mercury cup placed below and near the axis g2. A depending armt', attached to the axis g2 and movable with the core g, dips into themercury cup and is furnished therein with a wing 'i'. The arm t' and theaxis g2 are made of metal or other suitable electrical conductor.

J is a wire leading from the main wire B into the mercury cup I, andconstituting a part of a branch, which like the lamps is in parallel ormultiple are with the lamp circuit. In this branch is placed a lamp J',or other suitable resistance, which will prevent injury to the windingsof the magnets hereinafter mentioned, also in said branch.

K K are two opposing electro-magnets, the armatures 7s t of which areattached to a vibrating arm Il, pivoted at Z to the case or any othersuitable and convenient support. One

terminal of the winding of magnet K is connected by a wire 7e" with thecontact piece 71.', while the other terminal is connected by a wire nwith a contact spring N, with which IOO the arm L is adapted to engagewhen attracted by the magnet K. One terminal ofthe winding of magnet Kis connected by a wire k2 with the adjustable contact piece h2, whilethe other terminal of said winding is connected by a wire n' with acontact spring N, with which said lever L is adapted to engage whenattracted by the magnet K. The arm L is made of metal or other suitableelectrical conductor, and is connected through its pivot Z, by a wire f,with the neutral wire F. It will be observed that the index II and thewindings of magnets K Kare thus con neeted with the wires I3 and F inparallel, and are in the same relation theretothat a lampin the workingcircuit is to the "ire D or E and F. The arm L is provided "h insulatedmetallic contact blocks 1 and `.ich when the armatures 7.; 7:, are attomagnet K are adapted to engage w1` .i ".nd electrically connect thecontact springs or pieces m and m', m2 and m3. The wire B is connectedwith the contact piece fnl, the wire D with the contact piecem, the wireC with the contact piece m2, and the wire E with the contact piece fmi.It is obvious that the blocks l and Z2 and the contact springs or piecesm, m', m2 and m3, constitute switches by which the wires B and D and Cand E are connected or disconnected respectively.

My improved apparatus as above described operates as follows: Theadjustable contact piece h2 having been set at the proper point in thegraduated arc h, to permitI ot' the use of thc number of lamps agreedupon, but no more, the case is closed and securely locked to preventinterference with the apparatus, which is now ready for operation, andrequires no further attention or care. lVhen one or more lamps withinthe permitted number is turned into circuit, the current, traversing thcwindings of the solenoid G, encrgizes the same and draws the core g intothe samemore or less, according to the number of lamps in circuit. Theindex H is thereby swung away from the contact piece 7i toward thecontact piece h2, but so long as the number of lights in circuit is notabove the numberpermitted for which the instrument is set, the indexwill not engage the contact piece 7a2. It however, the number of lampsin circuit is increased above the number permitted, thc increased energyof the solenoid will carry the index H into engagement with the contactpiece h2, thereby closing the circuit through wire J, mercury cup I, armi, index H, contact piece h2, wire 752, the winding of magnet K', wirea', contact spring N', arm L, wire f, to the neutral wire F. Magnet Kbeingth us energized, attracts its armature and dra\ 's the arm L out ofengagement with the contact spring N into engagement with the contactspring N, thereby breaking the circuit through the winding ot magnet Kand at the same time disconnecting the wires B and D and C and E, andcutting all the lamps in the associated loop or branch out of circuit.The solenoid G being thus (le-energized, releases its core g,

and the index. H is permitted to gravitate slowly toward the contactpiece 7L with which it is arranged to engage when no current passesthrough the instrument. The backward movement of the index His retardedby the passage of the wing 2", through the mercury in cup I, the purposeof this device being to prevent a rapid vibration of the index H betweenthe contact pieces h and h2 and the consequent breaking and closing ofthe circuit through thelamps in rapid succession. The mercury cup I andarm t also serve to produce and maintain a more perfect electricalconnection between the wire J andthe index II than could be dependedupon if the connection were made through the bearings of axis g2. Assoon as the index II engages with the cont-act piece 7L the circuit isclosed through the branch, now including the contact piece h', wire 7c',winding of magnet K, wire n, contact spring N, arm L, wiref, from wire Bto the neutral wire F. Magnet K being thus energized attracts itsarmature, shifting the arm L out ot engagement with the spring N, intoengagement with the spring N. The circuit is thus broken through thebranch and established by the switch through the wires D and E and thelamps. Should the number of lamps in circuit still be greater than thatpermitted and tor which thc instrument is set, the index II will bedrawn into' engagement with the contact piece L2 and the lamps will beagain cut out as before stated. The engaging parts ot the index II andthe contact pieces 7L and h2 should be platinum plated or pointed toprevent corrosion.

In place of the lamp J', any other suitable resistance may be placed inthe branch, or the windings of the magnets K and K may be made to affordsutlicient resistance in themselves.

It is obvious that by moving the contact piece h2, the instrument may beset to permit of the use of any desired number of lamps, or both contactpieces may be made permanent and dilterent instruments made for use withdifferent numbers ot` lamps.

The details of the apparatus may be considerably modified within theintended scope of my invention.

Although I have for convenience shown and described my invention inconnection with a three wire incandescent electric light system, it isapplicable Ato other purposes.

I clair l. In an automatic out out the combination of a switch connectedwith and arranged to open and close the working circuit, two magnets,arranged one to open and the other to close said switch, two contactpieces connected respectively with the windings of said magnets, a partmovable in opposite directions into engagement with said contact piecesand connected with one side of an electric circuit the other side ofwhich has connections with the windings of said magnets, and a magnetarranged to actuate said movable part and IOC IIO

IZO

having its winding in or connected with the working circuit,substantially as and for the purposes set forth.

2. In an automatic cutout for electric lamp circuits, the combination ofa switch for opening and closing said circuit, magnets arranged to openand close said switch, two contact pieces connected respectively withthe windings of said magnets,a movable part in parallel with the lampcircuit, normally engaging the contact piece in connection with theclosing magnet, and a magnet having its winding connected with the lampcircuit and arranged to move said movable part toward the contact piecein connection with the opening magnet a distance corresponding with thestrength of the current in the lamp circuit, substantially as and i'orthe purposes set forth.

3. In an automatic cutout for electric lamp circuits, the combination ofa switch arranged to open and close the lamp circuit, magnets arrangedto open and close said switch, two contact pieces connected respectivelywith the windings of said magnets, a movable part in parallel with thelamp circuit, bearing normally against the contact piece in connectionwith the closing magnet when no current is passing through theinstrument, a magnet having its winding in or connected with the lampcircuit, arranged to draw said movable part toward the contact piece inconnection with the opening magnet, a distance corresponding with thestrength of the current in the lamp circuit, and a retarding device inconnection with said movable part, arranged to check its movement towardthe contact piece connected with the closing magnet, substantially asand for the purposes set forth.

4. In an automatic cut out for electric lamp circuits, the combinationof a switch arranged to open and close the lamp circuit, magnetsarranged to open and close said switch, a relatively tixed contact piececonnected with the winding of the closing magnet, an adjustable contactpiece connected with the winding ot` the opening magnet and movabletoward and from the relatively fixed contact piece, a movable part inparallel with the lamp circuit engaging normally with the ixed contactpiece when no current is passing through the instrument, and a magnethaving its winding in or connected with the lamp circuit, arranged todraw said movable part toward the adjustable contact piece a distancecorresponding with the strength of the current in the lamp circuit,substantially as and for the purposes set forth.

5. In an automatic cut out for electric lamp circuits,the combination ofaswitch connected with and arranged to open and close the lamp circuit,magnets arranged to operate said switch and having their windingsconnected respectively with contact pieces, a circuit breaker operatedby said magnets and connected with an electric circuit, two contactpieces connected respectively with the opposite terminals of saidwindings, a movable part arranged between the two last mention edcontact pieces and connected with the other side of the electric circuitwith which said circuit breaker is connected, and a magnet having itswinding in or connected with the lamp circuit and arranged to actuatesaid movable part, substantially as and for the purposes set forth.

G. In an automatic cut out for electric lamp circuits, the combinationof a switch for opening and closing the lamp circuits, magnets arrangedto open and close said switch, contact pieces connected respectivelywith the windings of said magnets, a part in parallel with the lampcircuit, movable in opposite directions between said contact pieces intoengagement therewith, and resting normally in engagement with thecontact piece connected with the closing n'iagnct when no curg rent ispassing through the instrument, a magnet in or connected with the lampcircuit, arranged to draw said movable part toward the other contactpiece, according to the strength ot the current in the lamp circuit, anda circuit breaker operated by the switch actuati ng magnets tobreak thecircuit through the winding ofthe magnet which last operated the switchand close it through the winding of the other magnet, substantially asand for the purposes set forth.

7. In an automatic cut out for electric lamp circuits, the combinationof a switch for openn ing and closing the lamp circuit, magnets arnranged to open and close said switch, two contact pieces connectedrespectively with the windings of said magnets, a vibrating arm movableat its free end between said contact points into engagement therewith, amagnet in or connected with the lamp circuit, arranged to draw said armtoward the contact piece connected with the winding of the switchopening magnet, and a mercury cup, into which dip a conductor connectedwith said vibrating arm and a conductor leading off from one of thewires of the lamp circuit, substantially as and for the purposes setforth.

8. In an automatic cut out for electric lamp circuits, the combinationof aswitch for openn ing and closing the lamp circuit, magnets ar rangedto open and close said switch, contact points connected respectivelywith the windings of said magnets, a vibrating arm movable between saidcontact pieces into engagement therewith, a magnethaving its winding inor connected with the lamp circuit and arranged to draw said arm. towardthe contact piece con nected with the winding of the switch openingmagnet, a wing attached to the axis of said vibrating arm, a mercury cupinto which said wing dips, and a conductor leading ott from one of thewires of the lamp circuit and di ppiug into the mercury cup, said wingserving to insure an electrical connection between the vibrating arm andsaid conn ductor and to retard the movement of said arm toward thecontact piece connected with IOO IIO

the windingof the switch closing magnet, substantially as and for thepurposes set forth.

9. In an automatic cut out for electric lamp circuits, the combinationof a switch for opening and closing the lamp circuit, magnets arrangedto open and close said switch, which consist ot` a vibrating arm towhich the armature of each of said magnets is attached, contact pieceswith which the terminals of the lamp circuit are connected, andinsulated metallic blocks connected with said arm and arranged toelectrically connect said contact pieces when moved into engagementtherewith, two contact pieces connected respectively with the windingsof said magnets, a Vibrating conducting arm movable between eer/gem

